1. Field of the Invention
This invention relates to sustained release preparation of growth hormone, especially human growth hormone.
2. Description of Related Disclosures
Sustained release delivery systems are of interest because they can improve patient compliance, tolerability, product performance, and expand the market potential for a product. The SABER system is a novel injectable liquid non-polymeric drug delivery system (Smith and Tipton (1996) Pharmaceutical Research 13(3):300). The SABER system, which stands for Sucrose Acetate isoButyrate Extended Release, is composed of sucrose acetate isobutyrate (SAIB) and a plasticizing solvent. SABER is injected as a low viscosity liquid that increases rapidly in viscosity after injection. The resulting high viscosity matrix is adhesive, biodegradable and biocompatible.
Clinically, rhGH is administered daily in growth hormone deficient (GHD) patients. To decrease the dosing frequency and increase patient compliance several sustained release formulations are under development. Recently the FDA approved the first rhGH sustained release formulation. This formulation allows patients to decrease their dosing interval from daily to once or twice per month depending on rhGH requirements. However, the approved Depot formulation releases 10–20% of the encapsulated protein in the first two days leading to high rhGH serum levels (Johnson et al., (1996) Nature Medicine (2):795–799).